中文摘要：

采用密度泛函理论（DFT）,我们研究了甲硅烷基（硅烯）钌配合物Cp＊Ru（CO）（=Si Mes2）Si Me3与甲醇发生反应的机理.整个反应机理包含以下四个步骤：（1）Ru=Si双键和甲醇发生1,2加成反应,随后通过消除Mes2Si（OMe）H生成Cp＊Ru（CO）Si Me3;（2）甲硅烷基配体上的甲基以1,2-甲基的迁移方式从硅原子转移到Ru原子上,并与甲醇发生1,2加成反应,生成的甲烷脱离后产生Cp＊Ru（CO）Si（OMe）Me2;（3）重复步骤（2）两次,得到甲氧基化的产物Cp＊Ru（CO）Si（OMe）3;（4）异腈配位Ru原子后得到最终的产物Cp＊Ru（CO）（CNt-Bu）Si（OMe）3.甲醇和Ru=Si双键的1,2加成是整个反应的决速步骤,自由能势垒为35.3 kcal/mol.此外,还研究了甲硅烷基（锗烯）钌配合物与甲醇的反应机理,相比硅烯配合物,锗烯配合物决速步的能垒相对较低,为31.8 kcal/mol.

英文摘要：

The mechanism for the reaction of a silyl（silylene） ruthenium complex Cp＊Ru（CO）（=Si Mes2）Si Me3 with methanol was investigated via the density functional theory（DFT） calculations. The mechanism includes four steps.（1） The reaction initiates via the 1,2-addition of methanol to the Ru = Si bond, followed by Mes2Si（OMe）H elimination to give Cp＊Ru（CO）Si Me3;（2） A methyl group of the silyl ligand migrates to Ru center via 1,2-Me migration, together with 1,2-addition of methanol, which is followed by the CH4 release to form Cp＊Ru（CO）Si（OMe）Me2;（3） Step（2） repeats twice to give the fully alkoxylated product Cp＊Ru（CO）Si（OMe）3.（4） Coordination of isonitrile affords final product Cp＊Ru（CO）（CNtBu）Si（OMe）3. The first step involving the 1,2-addition of methanol to the Ru=Si double bond is the rate-determining step for the whole reaction with a free energy barrier of 35.3 kcal/mol. The mechanism for the reaction of a silyl（germylene）ruthenium complex with methanol was also considered. The rate-determining step has relatively lower barrier of 31.8 kcal/mol in contrast to the silyl（silylene） ruthenium complex.